Cutting presses having fluid injection to post bearing for facilitating swinging of beam



May 21, 1968 R. w. HITCHCOCK 3,383,967

CUTTING PRESSES HAVING FLUID INJECTION TO POST BEARING FOR FACILITATINGSWINGING OF BEAM Filed May 1.2, 1966 3 Sheets-Sheet 1 {RN NR 1n venzorRichard Wfiz'zchcock By his Attorney y 1968 R. w. HITCHCOCK 3,383,967

CUTTING PRESSES HAVING FLUID INJECTION TO POST BEARING FOR FACILITATINGSWINGING OF BEAM Filed May 12, 1966 5 Sheets-Sheet 2 United StatesPatent 3,383,967 CUTTING PRESSES HAVING FLUHD INJECTIQN TO POST BEARHNGFOR FACRLETATENG SWING- lNG 0F BEAM Richard W. Hitchcock, Beverly,Mass., assignor to United Shoe Machinery Corporation, Flemington, N.J.,a corporation of New Jersey Filed May 12, 1966, Ser. No. 549,543 6Claims. (Cl. 83-538) ABSTRACT OF THE DISCLGSURE Manual swinging of thebeam of a cantilever cutting press is facilitated by supplying fluid,suitably air, under pressure to the bearing of the post on which thebeam is supported.

This invention relates to improvements in cutting presses and moreparticularly to improvements in presses of the type having a swingingbeam and commonly known as clickers, the improvement being directed tofacilitating the task of the operator in swinging the beam during thecourse of cutting operations.

The invention is illustrated as embodied in a press of the typedisclosed in US. Letters Patent No. 3,172,324 issued Mar. 9, 1965, on anapplication in the name of the present inventor. However, it will beappreciated that the invention is not confined to use with presses ofthis particular construction.

From a reading of the above patent as well as from other sources ofinformation regarding the manner of operation of such cutting presses,it will be understood that during the course of a days work in cuttingout parts, the operator must swing the beam or beams of a cutting pressmany times from a cutting position to a rest position in which suitableaccess to the workpiece and the cutting die is provided for setting upthe next cut. Depending on the size and position of the cutting die, thenecessary are of swing can vary from a small angle to as much as 90.Each time the operator swings a beam he must overcome the staticfriction between the post on which the beam is mounted and the bearingin which the post is journalled, this static friction being greaterafter the beam has remained for a time in a given position due torupture of the oil film where the weight of the beam pulls the postagainst the wall of the bearing.

Much effort has heretofore gone into making easier the task of theoperator in swinging a cutting beam; for example, much design effort hasgone into making beams lighter. Further various types of power means forassisting the swinging of the beam have been proposed. As cuttingpresses of the clicker type have become larger and more powerful, apractical limit appears to have been reached in designing a beam lightenough for manual swinging by the operator. On the other hand, theprovision of power means for assisting beam swing has the objection ofintroducing added complication and expense.

Accordingly, it is an object of the present invention to provide, in acutting press of the type having a cutting bed and a beam carried by avertical post journalled in a sleeve bearing for swinging over the bed,of means for reducing the effort required to swing the beam during thecutting operation. The bearing is commonly, and as illustrated, rigidwith the frame of the press, but it will be understood that theinvention is applicable to presses having a fixed post journalled in abearing rigid with the beam.

To this end and in accordance with a feature of the present invention,the manual swinging of such a beam is facilitated by admitting gaseousfluid under pressure to the 3,383,957 Patented May 21, 1968 ice spacebetwen the post on which the beam is supported and the sleeve bearing inwhich the post is journalled. The gaseous fluid preferably is introducedinto said space at a location wherein it is effective in exerting apressure against the post in a direction at least partially to offsetthe weight of the beam in pulling the post to one side of the bearing.However, there is a wide latitude of circumferential location; theapplication of such fluid under pressure to said space also is effectivein reducing starting effort even if applied at a location removed by ormore from the axis of the beam. Thus the gaseous fluid appears to havethe effect of forcing oil into the area of the bearing where itotherwise might be squeezed out with resulting metal to metal contact.For whatever reasons, however, the provision of such gaseous fluidsupply means has proved effective in reducing, to a large extent theeffort required to swing the beam.

Preferably, and in accordance with another feature of the presentinvention to avoid drying out the bearing lubricator, a small amount oflubricant is introduced into said space along with the gaseous fluid.

These and other features and advantages of the present invention willbest be understood from the following description taken together withthe accompanying drawings in which:

FIG. 1 is a rear elevation of apparatus embodying the present invention;

FIG. 2 is a plan view of the apparatus shown in FIG. 1;

FIG. 3 is a section taken on the line IlI-III of FIG. 1 on a scaleenlarged approximately five times; and

FIG. 4 is a diagrammatic view illustrating certain aspects of thepresent invention.

Only so much of the illustrative machine as is required to understandthe present invention will be described here in; the reader is referredto the above-mentioned patent for further details. Accordingly,referring now to FIGS. 1 and 2 of the drawings, the press shown thereincomprises a frame 10 carrying a cutting bed 12 on which the work issupported in cutting out parts. The frame 16 carries at opposite sidesof the bed 12 a pair of vertically oriented sleeve bearings 14 and 16 inwhich are journalled respectively two posts 18 and 20 to which swingbeams 22 and 24 are clamped. The beams are thus supported for movementtoward and away from the cutting bed in cutting strokes and for swingingabout the axes of the posts to the extent permitted by beam swing stopscomprising for the beam 22 a blade 26 and stop member 28 (FIG. 1).

Under certain cutting conditions it is necessary for the operator toswing the beams up to 90 from the position when centered over thecutting bed. For example where a large die such as the die 30 isemployed, it may be desirable to swing both beams rearwardly by about 90to provide convenient access for the operator and work in themanipulation thereof.

At the end of a cutting stroke when a post rises to the end of itsstroke from its sleeve bearing, the movement of the post in the hearingwill have provided a fresh film of oil between the surfaces of the postand the bearing, and if the operator immediately pushes the beam toclear it as he normally does, the static friction will be minimal atthis time. However, if the beam remains in one position for any lengthof time, for example, in the rear position, the effort required to swingthe beam is increased. To explain this, I have postulated that in thissituation while the operator is rearranging the work, a condition,diagrammed in greatly exaggerated form in FIG. 4, will develop in whichthe Weight of the beam will squeeze out or rupture the oil film,particularly in an area 32 at the upper end of the bearing on the sidetoward the beam and allow metal to metal contact to take place in thisarea.

I have found that the effort required to swing a beam 0 0,0 3 can begreatly reduced by supplying a portion of the space between the innersurface of the bearing and the post a gaseous fluid such as air.Preferably the fluid is supplied together with suflicient oil tomaintain an oil film in the critical areas of the mating surfaces of thebearing and post. Where the post and bearing have been pro-lubricated,supplying air alone to the hearing will suflice for a period, but in thelong run oil lost through natural es cape or through having beenexpelled by air pressure must be replaced and I prefer accordingly tointroduce a small amount of oil with the gaseous fluid supplied to thebearing. I believe, although I do not wish to be limited thereby, thatthe effect in reducing the starting effort results in part from theforce developed by the air pressure against the post tending tocounteract the weight of the beam and straightening up the post in thebearing, and perhaps in greater part from the eifect of the air pressurein forcing lubricating oil between the opposing surfaces in areas whereit will do the most good in preventing metai to metal contact.

Thus means for supplying gaseous fluid and oil to a portion of the spacebetween the post 18 and the sleeve bearing 14 of the illustrative presscomprises a pipethreaded male fitting 50 having a passage communicatingthrough an air port 51 (FIG. 2) formed in the bearing 14 with a portionof the space between the post 18 and the bearing, A flexible tube 52connects hte fitting 50 to a bulkhead fitting 54 supported in a bracket56 attached to the frame 10 of the machine. The bracket 56 serves tosupport a drip type oiler 60 the outlet means of which is connected tothe fitting 54, a T-fitting 62 and a reducing valve 64- arranged tocontrol the pressure of air supplied to the oiler from a supply meanscomprising an air hose 66. Corresponding elements on the right presserassembly are indicated by prime numerals. The pressure of the airsupplied to the oiler 6i and via a flexible tube 68 to an oiler 60'(FIG. 2) for the other hearing which is correspondingly connectedthereto, is indicated by a pressure gauge 72.

The air port 51 may be located circumferentially within a wide angularrange. It would seem that if the construction of the cutting presspermits, the air port 51 should preferably be located at a pointintermediate the extreme positions of the center line of the beam 22,that is within an are 80, FIG. 3, which indicates the normal arc ofmaximum swing of the center line of the beam 24. However, although as inthe case of the illustrative press, it is not always possible to disposethe fittings with the air port within this arc, I have found that evenwhen the air port is located beyond the normal extreme limit of the beamaxis as indicated by the angle 82, the starting effort for swinging thebeam back from its operating position is materially lessened by thesupply of air at this point. The heightwise location of the air port canbe varied within broad limits, but the port should be sufliciently belowthe top of the bearing to permit the application of an effective airpressure without excessive escape of air and oil at the top of thebearing.

In operation with each of the oilers, 60, 60' adjusted to provide aboutone drop each three minutes, air is supplied continuously to theadmission ports 51, 51' at a pressure regulated by the valve 64 whichpressure, while effective in reducing the necessary swing effort is lowenough to avoid. excessive escape of air and oil at the top of thehearing. The applied pressure may vary in range from about 10 to about40 psi. and a suitable pressure will be established by experience with aparticular machine. For exampie, I have found that a pressure of about10 to 15 p.s.i. is suitable for a press of the type illustrated.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. In a cutting press having a cutting bed and a beam carried by avertical post disposed at one side of the cutting bed, the post beingjournalled in a sleeve bearing for swinging of the beam over the bed, incombination therewith, means for supplying to a portion of the spacebetween the inner surface of the bearing and the post fluid at apressure greater than atmospheric.

2. Apparatus as in claim 1 wherein the fluid is a gaseous fluid.

3. Apparatus as in claim 1 wherein the fluid is a gaseous fluid havingentrained therein a relatively small amount of lubricating oil.

4. Apparatus as in claim 1 wherein said fluid is a gas eous fluid, saidmeans for supplying said fluid additionally comprising a drip type oilerfor entraining a relatively small amount of lubricating oil in thegaseous fluid supplied to said space.

5. In a cutting press, in combination, a cutting bed, a sleeve bearingdisposed with its axis vertically oriented at one side of said bed, saidbearing being formed with a radial port, a post journalled in saidbearing and a beam carried by said post for movement toward and awayfrom the cutting bed for dieing out work parts thereon and for swingingabout said axis and means comprising a conduit connected to said bearingand having a passage communicating through said port with the spacebetween the post and the bearing for supplying fluid under pressurebetween areas of the inner surface of the sleeve bearing and the outersurface of the post.

6. Apparatus as in claim 5 wherein said fluid supply means additionallycomprises valve means operative to regulate the pressure of gaseousfluid supplied to said conduit and means for supplying lubricating oilin controlled amount to said conduit.

References Cited UNITED STATES PATENTS Re 25,348 3/1963 Bissinger.

3,053,583 9/1962 Shaw. 3,231,320 1/1966 Kraift. 3,241,304 3/1966Mattingly et a1. 3,303,611 1/1967 Dunlap 3055 OTHER REFERENCESMcGraw-Hill Encyclopedia of Science and Technology, vol 2, p. 122,Fluid-Film Hydrostatic Bearings.

WILLIAM S. LAWSON, Primary Examiner.

